GO:0050816 phosphothreonine residue binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0050816 phosphothreonine residue binding is a molecular function defined as binding to a phosphorylated threonine residue within a protein.
• It is mediated by dedicated phosphothreonine-recognizing modules such as 14-3-3 proteins and FHA domains.
• These interactions convert phosphorylation marks into functional outputs including signal transduction, cell cycle control, and protein stability.
• FHA domains achieve specificity for phosphothreonine through a conserved pocket that discriminates phosphothreonine from phosphoserine.
• Dysregulated phosphothreonine-dependent interactions are implicated in cancer, mitotic defects, and other human diseases.
• CRISPR knockout, point-mutation, knock-in, and overexpression models enable causal testing of phosphothreonine-binding proteins.
Description
GO:0050816 phosphothreonine residue binding is a molecular function that describes the selective recognition of a phosphorylated threonine residue within a protein. Phosphorylation is a central regulatory modification, and the ability of effector proteins to read phosphothreonine marks is essential for converting kinase activity into downstream biological responses. This function is distinct from general phosphoprotein binding because it requires the phosphate group to be attached specifically to threonine, rather than serine or other residues.
phosphothreonine residue binding At A Glance
| GO ID | GO:0050816 |
|---|---|
| GO term | phosphothreonine residue binding |
| Ontology | molecular_function |
| Synonym | phosphothreonine binding |
| Definition | Binding to a phosphorylated threonine residue within a protein. |
| Major function | Recognition of phosphothreonine marks to mediate protein-protein interactions and signal transduction. |
| Representative domains | 14-3-3 proteins, FHA domains, and engineered phosphothreonine-binding domains. |
| Biological context | Cell cycle control, signal transduction, and protein complex assembly. |
What Is GO:0050816?
Phosphothreonine residue binding (GO:0050816) is the molecular function of selectively binding to a threonine residue that carries a phosphate group within a protein. It is a reader function: the binding protein recognizes the phosphorylated threonine as a docking site and uses that interaction to localize, assemble, or regulate protein complexes.
Why Is phosphothreonine residue binding Important in Cell Biology?
Phosphothreonine residue binding is important because it provides a reversible, phosphorylation-dependent switch for protein interactions. Many signaling pathways depend on reader proteins that bind phosphothreonine to propagate signals, control cell division, and regulate protein stability. Because these interactions are highly specific, they are attractive targets for research tools and therapeutic strategies.
• Converts kinase-mediated phosphorylation into functional protein-protein interactions.
• Enables signal transduction through modular phosphothreonine-binding domains such as 14-3-3 and FHA.
• Contributes to cell cycle and mitotic regulation.
• Supports protein complex assembly and localization.
• Provides a basis for engineered phosphothreonine-binding reagents.
• Links phosphorylation signaling to disease mechanisms including cancer.
• Facilitates study of kinase-substrate networks.
• Enables design of biosensors and affinity tools for phosphoproteomics.
• Helps interpret phosphoproteomic datasets by identifying reader-mediated interactions.
• Supports CRISPR-based causal testing of phosphothreonine-binding proteins.
Molecular Mechanism of phosphothreonine residue binding
Recognition of the phosphothreonine mark
In simple terms: The reader protein has a pocket that fits a phosphate attached to threonine.
Phosphothreonine residue binding begins with recognition of the phosphorylated threonine side chain by a dedicated binding module. The phosphate group provides key contacts, and the surrounding pocket discriminates phosphothreonine from phosphoserine.
Domain architecture of phosphothreonine readers
In simple terms: Different proteins use specialized domains to grab phosphothreonine.
14-3-3 proteins and FHA domains are well-characterized phosphothreonine-binding modules. FHA domains form a compact fold with a conserved phosphothreonine-binding pocket, while 14-3-3 proteins use a groove that accommodates phosphorylated residues in a sequence-dependent manner.
Specificity and discrimination
In simple terms: The reader can tell phosphothreonine apart from other phospho-residues.
Structural and biochemical studies show that FHA domains achieve specificity for phosphothreonine through a network of hydrogen bonds and steric constraints. This specificity is critical for accurate signal transmission and prevents inappropriate cross-talk with phosphoserine marks.
Functional consequences of binding
In simple terms: Once bound, the reader changes what the target protein does.
Binding of phosphothreonine can alter protein localization, activity, or stability, and can nucleate multiprotein complexes. For example, 14-3-3 binding can protect phosphorylated sites and modulate enzyme activity.
Engineered phosphothreonine-binding domains
In simple terms: Scientists can build custom readers for specific phosphothreonine sites.
Recombinant phosphothreonine-binding domains have been generated for defined phosphopeptides, such as a phosphopeptide of the human transcription factor c-Myc. Such engineered readers enable targeted detection and manipulation of phosphothreonine-dependent interactions.
Key Genes Involved in GO:0050816 phosphothreonine residue binding
The following genes and proteins represent major phosphothreonine-binding modules and related regulators.
| Gene | Major Role | Research Relevance |
|---|---|---|
| YWHAB | 14-3-3 protein that binds phosphothreonine motifs | Model for phosphothreonine-dependent signaling |
| YWHAG | 14-3-3 isoform involved in signal transduction | Study of isoform-specific phosphothreonine binding |
| SFN | 14-3-3 sigma, regulates cell cycle and stress responses | Cancer and cell cycle research |
| CHEK2 | Kinase that generates phosphothreonine marks for 14-3-3 binding | DNA damage response and cancer |
| CDC25C | Phosphatase regulated by phosphothreonine-dependent 14-3-3 binding | Mitotic regulation |
| MYC | Transcription factor with phosphothreonine sites recognized by engineered readers | Cancer and transcription research |
| PXN | Paxillin, scaffold with phosphothreonine-dependent interactions | Cell adhesion and signaling |
| AHA1 | Example of FHA-domain-containing protein | Phosphothreonine signaling studies |
| RAD53 | Kinase in yeast that phosphorylates threonine to create FHA docking sites | Model for FHA-phosphothreonine interactions |
| DUN1 | Yeast kinase involved in FHA-mediated phosphothreonine signaling | DNA damage checkpoint research |
| PTC2 | Phosphatase that reverses phosphothreonine marks | Mitotic regulation |
| PP2A | Phosphatase complex that removes phosphothreonine | Signal termination and cell cycle |
| H+-ATPase | Plant plasma membrane pump regulated by phosphothreonine and 14-3-3 binding | Plant signaling model |
| KSS1 | Yeast MAPK with phosphothreonine-dependent regulation | FHA domain research |
| FUS3 | Yeast MAPK regulated by phosphorylation | Phosphothreonine signaling |
| BUB1 | Kinase involved in mitotic checkpoint with phosphothreonine-dependent interactions | Mitosis research |
| PLK1 | Polo-like kinase 1, regulates phosphothreonine-dependent mitotic events | Cell cycle and cancer |
How Is phosphothreonine residue binding Regulated?
Phosphothreonine residue binding is regulated by the balance of kinases and phosphatases that add or remove the phosphate group. Protein phosphatases can reverse phosphothreonine marks, thereby terminating reader interactions. In addition, intrinsic disorder in 14-3-3 partners can modulate accessibility and binding affinity.
phosphothreonine residue binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CHEK2 | Cancer and DNA damage response | Knockout cell line |
| CDC25C | Mitotic defects and cancer | Point-mutation knock-in |
| SFN | Cancer and stress response | Overexpression model |
| MYC | Cancer and transcription | Engineered phosphothreonine-binding domain |
| PXN | Cell adhesion and signaling | Knockout and rescue |
Cancer
Phosphothreonine-dependent interactions are frequently dysregulated in cancer, where altered kinase and phosphatase activity changes reader recruitment. For example, 14-3-3 proteins and their phosphothreonine clients influence cell cycle progression and survival.
Mitotic and cell cycle disorders
Defects in phosphothreonine recognition can impair mitotic checkpoint control and chromosome segregation. Phosphatases that remove phosphothreonine marks are critical for mitotic exit, and their dysregulation contributes to genomic instability.
Signaling-related diseases
Because phosphothreonine binding underlies many signaling pathways, its disruption can affect diverse processes including stress responses and metabolism. Engineered readers are being developed to probe these interactions in disease contexts.
From phosphothreonine residue binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a phosphothreonine reader affect cell cycle progression? | CRISPR knockout |
| Does a specific phosphothreonine site mediate binding? | Point mutation of threonine to alanine |
| Can a phosphomimetic restore function? | Knock-in of phosphomimetic threonine to aspartate |
| Where does the reader localize? | Tagged knock-in with fluorescent protein |
| Does overexpression alter signaling? | Overexpression cell model |
| Which genes depend on phosphothreonine binding? | CRISPR library screening |
How to Study the phosphothreonine residue binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Phosphoproteomics | Phosphothreonine site identification | Mapping reader docking sites |
| Pull-down with recombinant domains | Direct binding to phosphothreonine | Validating reader-substrate interactions |
| Isothermal titration calorimetry | Binding affinity | Quantifying phosphothreonine recognition |
| X-ray crystallography | Three-dimensional structure | Defining phosphothreonine-binding pocket |
| NMR | Conformational changes upon binding | Studying dynamic interactions |
| Fluorescence polarization | Binding affinity in solution | Screening for inhibitors |
| CRISPR knockout | Loss-of-function phenotype | Testing causal roles |
| CRISPR library screening | Genome-wide dependencies | Identifying phosphothreonine-related pathways |
Phosphoproteomics
Mass spectrometry-based phosphoproteomics identifies phosphothreonine sites and their dynamics, providing candidate docking sites for reader proteins.
Binding assays
In vitro binding assays using recombinant domains, such as FHA domains or 14-3-3 proteins, measure direct phosphothreonine-dependent interactions.
Structural biology
X-ray crystallography and NMR reveal how phosphothreonine-binding pockets achieve specificity.
Cell-based reporter assays
Engineered phosphothreonine-binding domains can be used as reporters to detect specific phosphorylation events in cells.
How CRISPR Can Be Used to Study GO:0050816 phosphothreonine residue binding
Knockout
CRISPR knockout of phosphothreonine reader genes, such as 14-3-3 isoforms, can reveal their requirement in cell cycle and signaling.
Point Mutation
Point mutation of the phosphothreonine acceptor threonine to alanine prevents phosphorylation and binding, allowing tests of site-specific function.
Knock-in
Knock-in of phosphomimetic or tagged alleles enables tracking and functional analysis of phosphothreonine-dependent interactions.
Overexpression
Overexpression of phosphothreonine-binding proteins or engineered domains can amplify or perturb signaling pathways.
How EDITGENE Supports phosphothreonine residue binding Research
Researchers studying phosphothreonine residue binding-related genes often need to determine whether a candidate gene is causally involved in a specific signaling or disease phenotype. EDITGENE provides the CRISPR tools and models to move from correlation to causation.
Contact EDITGENE today to design your custom CRISPR model for phosphothreonine residue binding research.
Frequently Asked Questions About phosphothreonine residue binding
What is phosphothreonine residue binding?
It is the molecular function of selectively binding to a phosphorylated threonine residue within a protein, defined as GO:0050816.
What genes are involved in phosphothreonine residue binding?
Genes encoding 14-3-3 proteins (YWHAB, YWHAG, SFN), FHA-domain proteins, and kinases such as CHEK2 are involved.
What domains bind phosphothreonine?
14-3-3 proteins and FHA domains are the best-characterized phosphothreonine-binding modules.
How is phosphothreonine binding different from phosphoserine binding?
Phosphothreonine readers have pockets that discriminate the threonine side chain from serine, providing specificity.
What diseases are linked to phosphothreonine residue binding?
Cancer, mitotic defects, and signaling disorders have been linked to dysregulated phosphothreonine-dependent interactions.
How can I study phosphothreonine residue binding?
Phosphoproteomics, binding assays, structural biology, and CRISPR models are commonly used.
What is an FHA domain?
The FHA domain is a phosphothreonine-specific protein interaction module found in many signaling proteins.
Can CRISPR be used to study phosphothreonine binding?
Yes, knockout, point mutation, knock-in, and overexpression models can test the function of phosphothreonine readers.
What is the role of 14-3-3 proteins in phosphothreonine binding?
14-3-3 proteins bind phosphothreonine motifs to regulate localization, activity, and stability of target proteins.
Where can I get CRISPR models for phosphothreonine research?
EDITGENE provides knockout, point-mutation, knock-in, overexpression, and library screening services.
Conclusion
Phosphothreonine residue binding (GO:0050816) is a fundamental reader function that translates phosphorylation into biological outcomes. Understanding its mechanisms, key genes, and disease links requires robust experimental models, and CRISPR-based approaches offer precise tools for causal interrogation.
References
- 1. Yaffe MB et al.. 2001. Phosphoserine/threonine-binding domains.. Curr Opin Cell Biol 13(2):131-8 PMID: 11248545
- 2. Turner CE. 2000. Paxillin interactions.. J Cell Sci 113 Pt 23:4139-40 PMID: 11069756
- 3. Olsson A et al.. 1998. A phosphothreonine residue at the C-terminal end of the plasma membrane H+-ATPase is protected by fusicoccin-induced 14-3-3 binding.. Plant Physiol 118(2):551-5 PMID: 9765540
- 4. Mahajan A et al.. 2008. Structure and function of the phosphothreonine-specific FHA domain.. Sci Signal 1(51):re12 PMID: 19109241
- 5. Venegas LA et al.. 2018. Generating a recombinant phosphothreonine-binding domain for a phosphopeptide of the human transcription factor, c-Myc.. N Biotechnol 45:36-44 PMID: 29763736
- 6. Nilsson J. 2019. Protein phosphatases in the regulation of mitosis.. J Cell Biol 218(2):395-409 PMID: 30446607
- 7. Sluchanko NN et al.. 2019. Intrinsic disorder associated with 14-3-3 proteins and their partners.. Prog Mol Biol Transl Sci 166:19-61 PMID: 31521232
- 8. Li J et al.. 2000. The FHA domain mediates phosphoprotein interactions.. J Cell Sci 113 Pt 23:4143-9 PMID: 11069759
